Page 192 - TransAT_Tutorial_Manual

TransAT Tutorial Manual 4.5. Spillway

Simulation Parameters
In the Simulation Parameters tab, the numerical parameters of the simulation are set
(schemes, relaxation, time-stepping,...).

Simulation Type and Control Parameters
• Click Simulation Parameters on the left-hand side of the TransATUI

• Set the following parameters to solve for an unsteady flow

Simulation Type : Unsteady
Time Scheme : Euler 1 st Order

Control Parameters
Total Simulation time : 5.0
Max number of Time Steps : 100000
I n i t i a l Time Step : 0.001

Max number of I t e r a t i o n s per timestep : 40

Autorelaxation : ON
Relaxation Factor : 0.833

• For Time Stepping select Adaptive then click

• Set the following parameters in the Adaptive Time-Stepping window then click to save
the settings and close the window

CFL Limits Min : 0.5 Max: 0.9
D i ff u s i o n Min : 0.7 Max: 1.0

Equations
In this tab the convergence threshold is defined, as well as the convection scheme and the
solvers used by TransAT.

• Select Pressure in the equation tree and modify the parameters as follows

Convergence Tolerance : 1e−2
Solver : AMG, R−cycle Adaptive
Max Solver I t e r a t i o n s : 240
Relative Solver Tolerance : 0.01

• Select Other Variables in the equation tree and modify the parameters as follows

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